Vehicle seat track assembly

Abstract

Telescoping lower and upper tracks which comprises nested open channel sections. The lower track includes a three sided channel with opposing sides each forming one half of a bearing race. The open portion of the channel is defined by in-turned lips which enhance structural rigidity thereof. The upper track also includes a three sided channel with opposing sides forming the second half of a bearing race. The open portion of the channel is defined by outwardly extending lips which enhance structural rigidity thereof. A series of balls located in the bearing race established by the upper and lower track define a structural relationship therebetween. A retainer is disposed on the upper track and includes a laterally extending portion which occupies the opening defined by the inner track. The retainer limits the amount of dimensional displacement which may occur between the upper and lower tracks to an amount within the elastic range of deformation of the balls used to define the structural relationship therebetween.

I claim: 
     
       1. A track assembly comprising: a lower track telescopically disposed within an upper track;   said lower track formed as a first bilaterally symmetrical open channel section including a lower laterally extending portion connecting opposed upright portions;   each said upright portion formed as a first outwardly formed radius extending upwardly from said lower laterally extending portion which is connected with a first inwardly extending radius which is connected to a first vertically extending portion;   said first vertically extending portion including an in-turned lip formed at an angle less than 90° with respect thereto;   said upper track formed as a second bilaterally symmetrical open channel section including an upper laterally extending portion connecting opposed vertically extending members;   each said vertical member formed as a second outwardly formed radius extending downwardly from said upper laterally extending portion which is connected to a second vertically extending portion connected to a third outwardly extending radius connected to a third vertically extending portion connected to an outwardly extending lip;   said first inwardly extending radius of said lower track and said third outwardly extending radius of said upper track cooperating to form a channel;   a plurality of spherical members disposed in said channel and defining a structural interconnection between said lower and upper track;   a retainer plate connected to said laterally extending portion of said upper track including a first laterally extending portion having opposed wing portions formed at an upward angle with respect thereto; and   said opposed connected wing portions disposed within said open channel section formed by said lower track proximate said in-turned lip of said lower track.   
     
     
       2. The invention of claim 1 wherein said spherical members are resilient balls. 
     
     
       3. The invention of claim 1 wherein said upper track includes means to extend said upper laterally extending portion downwardly in a portion of said second open channel proximate said in-turned lip of said lower track. 
     
     
       4. The invention of claim 1 wherein said upper track includes a slot defined therein which slidingly receives a laterally displaceable link which is selectively engageable with one of a plurality of slots defined in said lower track. 
     
     
       5. The invention of claim 1 wherein said lower track upright portions form laterally extending tabs proximate end portions thereof which engage respective upwardly extending tabs defined on opposing end portions of said retainer plate to define end of travel limits of said track assembly. 
     
     
       6. The invention of claim 1 wherein said spherical members are resilient balls which are characterized by a predetermined limit of elastic deformation. 
     
     
       7. The invention of claim 6 wherein at least one of said in-turned lips of said lower track and said upper track laterally extending portion contact upon a deformation dimension less than said predetermined limit of said spherical members. 
     
     
       8. The invention of claim 6 wherein at least one of said in-turned lips of said lower track and a respective one of said wing portions of said retainer plate contact upon a deformation dimension less than said predetermined limit of said spherical members. 
     
     
       9. A track assembly comprising: a first track telescopically received within a second track;   said first track formed as a bilaterally symmetrical open channel member defining a first opening including a first laterally extending portion connected to opposed vertically extending side portions which each define a first one-half of a bearing race;   said vertically extending side portions terminating as inwardly extending lip members;   said second rack formed as a bilaterally symmetrical open channel member defining a second opening including a second laterally extending portion connected to opposed vertically extending side portions which define a second one-half of a bearing race;   said first and second one-half of a bearing race forming a channel with spherical members disposed therein and defining a telescopic structural relation between said first and second track;   a retainer disposed on said second track including a laterally extending portion disposed in said first opening of said first track; and   said retainer, said inwardly extending lip members, and said second laterally extending portion defining a structural limit of deformation between said first and second track which is a dimension less than the limit of elastic deformation of said spherical members.   
     
     
       10. The invention of claim 9 wherein said spherical members are resilient balls. 
     
     
       11. The invention of claim 9 wherein said inwardly extending lip members of said first track are oriented to said side portions at an angle less than 90°. 
     
     
       12. The invention of claim 9 wherein said second track includes means to extend said second laterally extending portion downwardly into said second opening proximate said inwardly turned lip members. 
     
     
       13. The invention of claim 9 wherein said second track includes a slot defined therein which slidingly receives a laterally displaceable link which is selectively engageable with one of a plurality of slots defined in said first track. 
     
     
       14. The invention of claim 9 wherein at least one of said opposed vertically extending portions form laterally extending tabs proximate end portions thereof which engage respective upwardly extending tabs defined on opposing end portions of said retainer to define end of travel limits of said track assembly. 
     
     
       15. The invention of claim 9 wherein said retainer comprises a laterally extending portion having opposed wing portions formed at an upward angle.